Constructing method of airborne radar space-time two-dimensional filter based on clutter covariance matrix

Abstract

The invention discloses a constructing method of an airborne radar space-time two-dimensional filter based on clutter covariance matrix reconstruction, which belongs to the technical field of radar signal processing and mainly solves the problems that the existing filtering technique has high requirement on data training samples, large operand for filtering clutter and poor real-time application performance. The constructing method comprises the following implementation steps of: firstly, constructing clutter covariance matrix according to the movement velocity and working parameters of the radar; next, realizing random clutter covariance matrix reconstruction by changing space-time relevant functions and adjusting clutter bandwidth; then, designing a group of filters with different notch widths based on a Wiener filtering principle; and finally, conducting nonlinear selection to filter coefficients according to a minimum residual energy criterion so as to obtain the optimal airborne radar space-time two-dimensional filter. Simulation analysis and measured data indicate that the constructing method has better clutter inhibition performance and moving-target detection performance when processing heterogeneous clutter environmental data compared with the small degree of freedom dimension-reducing self-adaptive method.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing, and specifically relates to a filter construction method, which can be used to design an optimal space-time two-dimensional filter for airborne radar, and realize effective suppression of clutter and target detection. Background technique [0002] Airborne pulse Doppler radar is one of the most important military sensors on the modern battlefield, and moving target detection is an important function of it. Since the airborne radar is installed on a very high aircraft platform, it can effectively overcome the occlusion problem in the ground radar, and the visual distance to low-altitude targets is much farther than that of the ground-based radar, so it has been widely valued. In addition to being used as an airborne early warning radar for long-range early warning, airborne radar can also be used as an airborne fire control radar for attack missions. [0003] Airborne radar is oft...

AI Technical Summary

Problems solved by technology

[0006] 1. Due to the tens of thousands of dimensions of the adaptive processor, it is necessary to invert the high-dimensional covariance matrix, and the amount of calculation and equipment is astonishing, which cannot be processed in real time;

[0007] 2. Since the covariance matrix needs to be estimated by statistical average, at least 2 times the number of processor dimensions is required to satisfy the independent and identically distributed range unit sample data, which is very important in the actual airborne radar clutter environment, especially in the non-uniform environment unsatisfactory

However, this method does not consider the effects of space-time decorrelation and antenna pattern modulation; in addition, since the phased array radar receives clutter in an omnidirectional range in this method, it introduces non-target area clutter, so the Multi- SAR clutter model using phased array radar clutter covariance matrix reconstruction to solve the filter weight vector has certain limitations, resulting in a decline in clutter suppression performance

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